Guillain-Barré syndrome in a local area in Japan, 2006-2015: an epidemiological and clinical study of 108 patients.

BACKGROUND AND PURPOSE: Many epidemiological studies of Guillain-Barré syndrome (GBS) and Fisher syndrome (FS) have been conducted in Europe and America. In contrast, epidemiological studies are rare in Asia where the GBS subtypes differ from those in Western countries. This study was undertaken to clarify the incidence of GBS and FS in a local area in Japan as well as their seasonal trends. METHOD: Seventy-one GBS and 37 FS patients were recorded from 2006 to 2015 in an area of approximately 1.5 million inhabitants in Japan. The incidence, seasonal trends and clinical features of GBS and FS were examined. RESULTS: The incidence rate of GBS was 0.42 cases per 100 000 person-years and that of FS was 0.22 cases per 100 000 person-years. The incidence of GBS increased with age and FS affected predominantly patients aged from 45 to 64 years old. There was some seasonal clustering of acute motor axonal neuropathy (AMAN) and FS in spring and summer, but it was not significant. AMAN and FS patients had a high frequency of preceding infection (AMAN, 68% gastrointestinal infection; FS, 65% upper respiratory infection). Antecedent respiratory infection was significantly associated with FS as an outcome. Serum antibodies to ganglioside GM1 were detected in 71% of AMAN patients and antibodies to GQ1b were detected in 81% of FS patients. CONCLUSIONS: Our study offers evidence of a lower incidence of GBS and a higher incidence of FS in a local area in Japan than in Western countries.

The upr-1 gene encodes a catalytic subunit of the DNA polymerase zeta which is involved in damage-induced mutagenesis in Neurospora crassa.

The upr-1 mutant was one of the first mutagen-sensitive mutants to be isolated in Neurospora crassa. However, the function of the upr-1 gene has not yet been elucidated, although some genetic and biochemical data have been accumulated. In order to clone the upr-1 gene, we performed a chromosome walk from the mat locus, the closest genetic marker to upr-1 for which a molecular probe was available, towards the centromere, and a chromosomal contig of about 300-400 kb was constructed. Some of these clones complemented the temperature sensitivity of the un-16 mutation, which is located between mat and upr-1. The un-16 gene was sequenced, and localized in the MIPS Neurospora crassa genome database. We then searched the regions flanking un-16 for homologs of known DNA repair genes, and found a gene homologous to the REV3 gene of budding yeast. The phenotype of the upr-1 mutant is similar to that of the yeast rev3 mutant. An ncrev3 mutant carrying mutations in the N. crassa REV3 homolog was constructed using the RIP (repeat-induced point mutation) process. The spectrum of mutagen sensitivity of the ncrev3 mutant was similar to that of the upr-1 mutant. Complementation tests between the upr-1 and ncrev3 mutations indicated that the upr-1 gene is in fact identical to the ncrev3 gene. To clarify the role of the upr-1 gene in DNA repair, the frequency of MMS and 4NQO-induced mutations was assayed using the ad-8 reversion test. The upr-1 mutant was about 10 times less sensitive to both chemicals than the wild type. The expression level of the upr-1 gene is increased on exposure to UV irradiation in the uvs-2 and mus-8 mutants, which belong to postreplication repair group, as well as in the wild type. All these results suggest that the product of the upr-1 gene functions in damage-induced mutagenesis and DNA translesion synthesis in N. crassa.

A study of raphide microstructure in relation to irritation.

Raphides from fourteen genera in seven families of flowering plants were examined using light and scanning electron microscopy. Raphides from an additional fifteen genera were described from literature. Of these thirty-four plants, fourteen were known to cause irritation. Barbs are associated with irritation in the families Araceae and Leeaceae, but not Vitaceae. Of the seventeen taxa described that contain raphides with barbs, six also have grooves on their crystals. The relationship between grooves and irritation is inconsistent. In seven examples in the family Araceae, raphides with grooves are associated with irritation. In three examples, one in the family Araceae and two in the Lemnaceae, raphides with grooves are present with little or no associated irritation. Plants that contain raphides without barbs or grooves are associated with irritation only if the raphides are greater than 180 microns in length. Four taxa that contain raphides longer than 180 microns without barbs or grooves are associated with irritation. However, nine taxa that contain raphides shorter than 180 microns without barbs or grooves do not cause irritation. It appears that raphide microstructure and size both contribute to irritation. However, the lack of a consistent association of barbs and grooves with irritation does not rule out the additional presence of a chemical toxin.

The effect of growth in 99.8 deuterium oxide on the ultrastructure of winter rye.

A preliminary report dealing with the ultrastructural effects of culture in a 99.8% D(2)O (deuterium oxide) environment on winter rye (Secale cereale L. cv. Winter) is presented. In general, the cells of D(2)O-cultured seedlings appeared similar to the cells of H(2)O-cultured seedlings. However, differences were found in chloroplast and dictyosome morphology, and ribosome number.

Raphides with barbs and grooves in Xanthosoma sagittifolium (Araceae).

Raphides in petioles of Xanthosoma sagittifolium are needlelike crystals about 50 micrometers long. The rectangular cross sections have maximum dimensions of approximately 850 by 250 nanometers. The raphides have two distinct end structures. One end is narrow, acute, and tapered to a point; the other is broad, acute, and abruptly pointed. Barbs, about 750 angstroms long with tips oriented away from the narrow end, occur along the length of the raphide on ridges on either side of two longitudinal grooves. These grooves, located opposite each other, give the raphide cross section an H-shape.